JPH05341518A - Photosensitive composition - Google Patents

Abstract

PURPOSE:To provide a photosensitive compsn. excellent in contrast and developability. CONSTITUTION:This photosensitive compsn. contains a mixture of an o- quinonediazido compd. having >=3,000mol.wt. with a compd. obtd. by condensing o-quinonediazidosulfonyl halide and trihydroxybenzophenone or a mixture of a compd. obtd. by condensing pyrogallol-acetone resin having >=3,000 mol.wt. and o-quinonediazidosulfonyl halide with a compd. obtd. by condensing pyrogallol-acetone resin having <=2,000 mol.wt. and o-quinonediazidosulfonyl halide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive composition, and more particularly to a photosensitive composition having both excellent contrast and developability.

[0002]

2. Description of the Related Art A photosensitive lithographic printing plate is one in which an ink-receptive photosensitive layer is provided on a hydrophilic support. For example, in a positive type photosensitive lithographic printing plate, an ultraviolet ray or the like on the hydrophilic support is used. An ink-receptive photosensitive layer that is solubilized by exposure to actinic rays is formed. When the photosensitive layer of such a positive type photosensitive lithographic printing plate is imagewise exposed from an original and then developed, the photosensitive layer in the exposed portion is removed and the surface of the hydrophilic support is exposed, while the photosensitive portion in the unexposed portion is exposed. The layer remains on the support to form the ink receiving layer.

However, when exposing the original film using such a photosensitive lithographic printing plate, if foreign matter such as dust adheres to the original film or the photosensitive lithographic printing plate, the adhered portion will be extremely exposed. There was a risk that a small amount of light would enter and it would not be possible to form a sharp resist image (burning phenomenon).

Further, when a conventional lithographic printing plate is exposed to a white lamp (fluorescent lamp) for a long time (about 10 minutes) and developed, the photosensitive layer of the printing plate is thinned due to exposure to light, and the lithographic printing plate is not yet exposed. There was a problem that the exposed part was also developed (safelight property).

Therefore, development of a lithographic printing plate excellent in high contrast such that a sharp resist image can be obtained even if foreign matter such as dust adheres to the original film or the photosensitive lithographic printing plate is underway.

As one of the conventional techniques for increasing the contrast, a surfactant such as polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene higher alcohol ether, etc. is exposed to light. There is a method of adding o-naphthoquinonediazide-4-sulfonic acid to a compound containing an orthoquinonediazide group or a compound containing an orthoquinonediazide group.

However, even if a support having been subjected to a conventional graining treatment is coated with such a high-sensitivity photosensitive layer, a film of the exposure layer remains on the support after exposure and development, which causes a problem in developability. was there.

Therefore, it is desired to develop a photosensitive composition which improves the workability such as the above-mentioned burning blur phenomenon and safelight property and does not impair the developability.

[0009]

SUMMARY OF THE INVENTION Therefore, the present invention has been made in view of the above-mentioned problems of the prior art, and is burned by foreign matter such as dust existing between the original film and the photosensitive lithographic printing plate during exposure. It is an object of the present invention to provide a photosensitive composition which has no blur phenomenon, does not cause film loss even after working for a long time under white light, and has good developability.

[0010]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies on a photosensitive composition in order to achieve the above object, and as a result, an orthoquinone diazide compound having a molecular weight of 3000 or more and an orthoquinone diazide sulfonyl halide were prepared. A photosensitive composition containing a mixture with a compound condensed with trihydroxybenzophenone, or a compound and a molecular weight obtained by condensing a pyrogallol acetone resin having a molecular weight of 3000 or more with an orthoquinone diazide sulfonyl halide.
It is known that a photosensitive composition containing a mixture of a pyrogallol-acetone resin of 2000 or less and a compound obtained by condensing an orthoquinone diazide sulfonyl halide does not have a so-called baking blur phenomenon or a film reduction state and is excellent in developability at the same time. The present invention has been completed.

The present invention will be described in more detail below.

Generally, the photosensitive composition comprises (a) an orthoquinonediazide compound, (b) an alkali-soluble resin, and (c).
A compound which generates an acid or a free radical upon exposure to light, (d)
It contains a dye which changes its color tone by interacting with the photolysis product of (c) and (e) an organic acid and an acid anhydride.

Among them, in the photosensitive composition of the present invention, the orthoquinonediazide compound having a molecular weight of 3000 or more as a photosensitive component and a mixture of a compound obtained by condensing an orthoquinonediazidesulfonyl halide and trihydroxybenzophenone, or a molecular weight Is characterized by using a mixture of a compound of condensed pyrogallol-acetone resin with 3000 or more and orthoquinone diazide sulfonyl halide and a compound with condensed molecular weight of 2000 or less pyrogallol-acetone resin and orthoquinone diazide sulfonyl halide. is there.

The orthoquinonediazide compound having a molecular weight of 3000 or more used as a part of the photosensitive component of the present invention is
It is a reaction product of a compound containing an orthoquinonediazide group and an alkali-soluble resin having a molecular weight of 3000 or more.

The reaction product of a compound containing an orthoquinonediazide group and an alkali-soluble resin has a molecular weight of 3,000 or more, which is o-naphthoquinonediazide-5-.
Examples thereof include ester compounds of sulfonic acid and polycondensation resins of phenols and aldehydes or ketones. In the present invention, this ester compound has a molecular weight of 3000 or more. Here, the molecular weight of 3000 or more means that the molecular weight of the trunk polymer excluding the compound containing the orthonaphthoquinonediazide group in the ester compound as the reaction product is 30
It is 00 or more. This molecular weight is preferably 3000
~ 15,000. If the molecular weight is 3,000 or less, a hard lithographic printing plate having a high contrast (excellent in baking blur and safe light) cannot be obtained. If the molecular weight is 15,000 or more, the developability is poor.

Examples of the phenols used for producing the polycondensation resin include phenol, o-cresol, m-cresol, p-cresol, 3,5-xylenol, carvacrol, monohydric phenol such as thymol, catechol, resorcin, Divalent phenol such as hydroquinone,
Examples include trivalent phenols such as pyrogallol and phloroglucin.

Examples of the aldehyde include formaldehyde, benzaldehyde, acetaldehyde, crotonaldehyde and furfural. Preferred among these aldehydes are formaldehyde and benzaldehyde.

As the ketone, for example, acetone,
Methyl ethyl ketone may be mentioned.

Specific examples of the polycondensation resin include phenol / formaldehyde resin, m-cresol / formaldehyde resin, m-, p-mixed cresol / formaldehyde resin, resorcin / benzaldehyde resin, pyrogallol / acetone resin. .. All of these have a molecular weight of 3000 or more.

The polycondensation resin of these phenols and aldehyde or ketone can be produced by a known method. The polycondensation resin produced by this has a molecular weight of
It is more than 3000, and such a polymer can be made to have a predetermined molecular weight by adjusting the amount of phosphorus oxychloride (POCl ₃ ) as a catalyst during the reaction and the temperature for a suitable time.

Another preferable example of the orthoquinonediazide compound having a molecular weight of 3000 or more is an ester compound of o-naphthoquinonediazide sulfonic acid and a vinyl polymer having a phenolic hydroxyl group.

As the vinyl polymer having a phenolic hydroxyl group which forms such an ester compound, the vinyl polymer having a phenolic hydroxyl group described in Japanese Patent Application No. 2-29709 can be used.

The photosensitive component of the present invention has a molecular weight of 3000.
A condensed compound of orthoquinone diazide sulfonyl halide and 2,3,4-trihydroxybenzophenone is used together with the above orthoquinone diazide compound. The ratio of these high molecular weight photosensitive components (former) to the photosensitive components of the monomer is 9.5: 0.5 to 1.5: 8.5.

According to another preferred embodiment of the photosensitive component of the present invention, a condensation product of a pyrogallol-acetone resin having a molecular weight of 3000 or more and an orthoquinone diazide sulfonyl halide, a pyrogallol-acetone resin having a molecular weight of 2000 or more, and an orthoquinone diazide. Mixtures of sulfonyl halides with condensation products are used. The mixing ratio of these high molecular weight photosensitive components (former) and low molecular weight photosensitive components is 0.5.
/9.5 to 8/2.

The proportion of the photosensitive component of the present invention in the photosensitive composition is preferably 5 to 60% by weight, particularly preferably
10 to 50% by weight.

It is preferable to use an alkali-soluble resin in the photosensitive composition of the present invention.

Examples of the alkali-soluble resin include novolac resins, vinyl polymers having phenolic hydroxyl groups, condensation resins of polyhydric phenols and aldehydes or ketones described in JP-A-55-57841. .. Also, these resins can be used in combination.

Examples of novolac resins include phenol / formaldehyde resins, cresol / formaldehyde resins, phenol / cresol / formaldehyde copolycondensation resins as described in JP-A-55-57841, JP-A-55-127553. P-substituted phenol or cresol.
Formaldehyde copolycondensation resin etc. are mentioned.

Examples of the non-novolak resin include vinyl polymers having a phenolic hydroxyl group, particularly vinyl polymers having a unit having a phenolic hydroxyl group in the molecular structure.

The proportion of the alkali-soluble resin in the photosensitive composition of the present invention is preferably 50 to 95% by weight, more preferably 60 to 90% by weight.

Considering the coatability, these alkali-soluble resins preferably have a weight average molecular weight of 1,000 or more, more preferably 1,500 or more.

The photosensitive composition of the present invention may contain a compound capable of generating an acid or a free radical upon exposure. Examples of such a compound are represented by the following general formulas [I] and [II]. The trihaloalkyl compound or diazonium salt compound shown is preferably used.

[0033]

[Chemical 1] (In the formula, Xa represents a trihaloalkyl group having 1 to 3 carbon atoms, W represents each atom of N, S, Se, P, and C,
Z represents each atom of O, N, S, Se and P. Y represents a nonmetallic atom group which has a chromophore group and is necessary for cyclizing W and Z. However, the ring formed by the non-metal atomic group may have Xa. )

The general formula ^{_{[II] Ar-N 2 +}} X - ( wherein, Ar represents an aryl group, X represents a counter ion of an inorganic compound.)

Specifically, for example, as the trihaloalkyl compound of the general formula [I], the following general formulas [III] and [I
V] or a compound represented by [V] is included.

[0036]

[Chemical 2] (In the formula, Xa represents a trihaloalkyl group having 1 to 3 carbon atoms, L represents a hydrogen atom or a methyl group, J represents a substituted or unsubstituted aryl group or a heterocyclic group, and n is 0, 1 or 2. .)

Specific examples of the compound represented by the general formula [III] include

[0038]

[Chemical 3] An oxadiazole compound having a benzofuran ring such as
2-Trichloromethyl-5- (p-methoxystyryl) -1,3,4-described in JP-A-54-74728
Oxadiazole compound, or

[0039]

[Chemical 4]

[0040]

[Chemical 5]

[0041]

[Chemical 6] Etc.

The compound represented by the general formula [IV] or [V] is specifically described in 4- (2,4-dimethoxy-4-styryl) described in JP-A-53-36223. ) -6-Trichloromethyl-2-pyrone compound, 2,4-bis- (trichloromethyl) -6-p-methoxystyryl-S-triazine compound described in JP-A-48-36281, 2, 4-bis- (trichloromethyl)
A 6-p-dimethylaminostyryl-S-triazine compound and the like can be mentioned.

On the other hand, the diazonium salt compound is preferably a diazonium salt capable of generating a strong Lewis acid upon exposure, and the counterion of an inorganic compound is recommended as the counterion portion. As a specific example of such a compound, the anion portion of the diazonium salt is at least one kind of phosphorus fluoride ion, arsenic fluoride ion, antimony fluoride ion, antimony chloride ion, tin chloride ion, bismuth chloride ion and zinc chloride ion. An aromatic diazonium salt may be mentioned, and preferably a paradiazophenylamine salt may be mentioned.

The amount of the compound which forms an acid or a free radical upon exposure to light is preferably 0.01 to 20% by weight, more preferably 0.1 to 20% by weight, and particularly preferably 0.2 to 10% by weight in the total photosensitive layer composition. %.

In the photosensitive composition of the present invention, together with the above-mentioned compound which forms an acid or a free radical upon exposure,
A color-changing agent is included that alters the color tone by interacting with the photodegradation product. There are two types of such discoloring agents, one that develops color and the other that discolors or discolors. As the discoloring agent that discolors or discolors, various dyes such as diphenylmethane, triphenylmethane-based thiazine, oxazine-based, xanthene-based, anthraquinone-based, iminonaphthoquinone-based, and azomethine-based dyes are effectively used.

Specific examples of these are as follows. Brilliant Green, Eosin,
Ethyl violet, erythrosine B, methyl green, crystal violet, basic fuchsine, phenolphthalein, 1,3-diphenyltriazine,
Alizarin Red S, thymolphthalein, methyl violet 2B, quinaldine red, rose bengal, methanyl yellow, thymol sulfophthalein, xylenol blue, methyl orange, orange IV, diphenylthiocarbazone, 2,7-dichlorofluorescein, para Methyl Red, Congo Red, Benzopurpurin 4
B, α-naphthyl red, Nile blue 2B, Nile blue A, phenacetaline, methyl violet, malachite green, parafuchsin, Victoria pure blue BOH (Hodogaya Chemical Co., Ltd.), oil blue # 603
[Orient Chemical Co., Ltd.], Oil Pink # 312
[Orient Chemical Co., Ltd.], Oil Red 5B
[Orient Chemical Co., Ltd.], Oil Scarlet # 308 [Orient Chemical Co., Ltd.], Oil Red OG [Orient Chemical Co., Ltd.], Oil Red R
R [manufactured by Orient Chemical Industry Co., Ltd.], oil green #
502 [manufactured by Orient Chemical Industry Co., Ltd.], Spiron Red BEH Special [manufactured by Hodogaya Chemical Industry Co., Ltd.], m-
Cresol purple, cresol red, rhodamine B, rhodamine 6G, first acid violet R, sulforhodamine B, auramine, 4-p-diethylaminophenyliminonaphthoquinone, 2-carboxyanilino-4-p-diethylaminophenyliminonaphthoquinone, 2-carb Stearylamino-4-p-dihydrooxyethylamino-phenyliminonaphthoquinone, p-methoxybenzoyl-p'-diethylamino-
o'-methylphenyliminoacetanilide, cyano-
p-diethylaminophenyliminoacetanilide, 1
-Phenyl-3-methyl-4-p-diethylaminophenylimino-5-pyrazolone, 1-β-naphthyl-4-
p-Diethylaminophenylimino-5-pyrazolone.

Further, arylamines can be used as the color-changing agent that develops color. Aryl amines suitable for this purpose include so-called leuco dyes in addition to simple aryl amines such as primary and secondary aromatic amines, and examples thereof include the following.

Diphenylamine, dibenzylaniline,
Triphenylamine, diethylaniline, diphenyl-
p-phenylenediamine, p-toluidine, 4,4'-
Biphenyldiamine, o-chloroaniline, o-bromoaniline, 4-chloro-o-phenylenediamine, o-
Bromo-N, N-dimethylaniline, 1,2,3-triphenylguanidine, naphthylamine, diaminodiphenylmethane, aniline, 2,5-dichloroaniline, N
-Methyldiphenylamine, o-toluidine, p, p '
-Tetramethyldiaminodiphenylmethane, N, N-dimethyl-p-phenylenediamine, 1,2-dianilinoethylene, p, p ', p "-hexamethyltriaminotriphenylmethane, p, p'-tetramethyldiaminotriamine Phenylmethane, p, p'-tetramethyldiaminodiphenylmethylimine, p, p ', p "-triamino-
o-methyltriphenylmethane, p, p ′, p ″ -triaminotriphenylcarbinol, p, p′-tetramethylaminodiphenyl-4-anilinonaphthylmethane,
p, p ', p "-triaminotriphenylmethane, p,
p ', p "-hexapropyltriaminotriphenylmethane.

In the present invention, among the above color changing agents, dyes capable of changing color in the pH range 1 to 5 are preferable.

The proportion of the above-mentioned discoloring agent in the photosensitive composition is preferably 0.01 to 10% by weight, more preferably 0.02 to 5% by weight.

The photosensitive composition of the present invention preferably further contains various organic acids and acid anhydrides.

As the above-mentioned organic acid, all known various organic acids can be mentioned, but an organic acid having a pKa value of 2 or more is preferred, a pKa value of 3.0 to 9.0 is more preferred, and a 3.5 to 8.0 is particularly preferred. Organic acids are used. However, the pKa value used in the present invention is the value at 25 ° C.

Examples of such an organic acid include the organic acids described in Kagaku Binran Basic Edition II (Maruzen Co., Ltd., 1966, pp. 1054-1058), which are compounds capable of exhibiting the pKa value of the present invention. Can be mentioned. Examples of such compounds include benzoic acid, adipic acid, azelaic acid, isophthalic acid, p-toluic acid, q-toluic acid, β-ethylglutaric acid, m-oxybenzoic acid, p-oxybenzoic acid, 3, 5-dimethylbenzoic acid, 3,4-dimethoxybenzoic acid, glyceric acid, glutaconic acid, glutaric acid, p
-Anisic acid, succinic acid, sebacic acid, β, β-diethylglutaric acid, 1,1-cyclobutanedicarboxylic acid, 1,
3-cyclobutanedicarboxylic acid, 1,1-cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, β, β-dimethylglutaric acid, dimethylmalonic acid, α-tartaric acid, suberin Acid, terephthalic acid, pimelic acid, phthalic acid, fumaric acid, β-propylglutaric acid, propylmalonic acid, mandelic acid, mesotartaric acid, β-methylglutaric acid, β, β
-Methylpropylglutaric acid, methylmalonic acid, malic acid, 1,1-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, cis-4-cyclohexene 1,2-dicarboxylic acid etc. can be mentioned. In addition, organic acids having an enol structure such as Meldrum's acid and ascorbic acid can also be preferably used. The ratio of the organic acid in the photosensitive layer is 0.05.
-10% by weight is suitable, preferably 0.1-5% by weight.

As the acid anhydride used in the present invention, all known various acid anhydrides can be used, but cyclic acid anhydrides are preferable, and examples thereof include phthalic anhydride and tetrahydrophthalic anhydride. , hexahydrophthalic anhydride, 3,6-oxy - △ ⁴ - tetrahydrophthalic anhydride, tetrachlorophthalic anhydride, glutaric acid anhydride, maleic acid anhydride, chlorosulfonic maleic acid, alpha-
Examples thereof include phenyl maleic anhydride, succinic anhydride, and pyromellitic acid. These acid anhydrides are contained in the photosensitive layer in an amount of 0.05
It is preferably contained in an amount of 10 to 10% by weight, particularly 0.1 to 5% by weight.

The photosensitive composition of the present invention can achieve the object of the present invention by combining the above-mentioned materials, and particularly by containing the compound of the present invention. Besides, dyes such as dyes and pigments, sensitizers, plasticizers, and surfactants may be added, if necessary.

Further, each of these components is dissolved in the following solvent, and this is further coated on the surface of a suitable support and dried to form a photosensitive layer, thereby forming a photosensitive lithographic printing plate. ..

Solvents that can be used for dissolving each component of the photosensitive composition of the present invention include methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve, cellosolves such as ethyl cellosolve acetate, dimethylformamide, dimethylsulfoxide, dioxane. , Acetone, cyclohexanone, trichloroethylene, methyl ethyl ketone and the like. These solvents can be used alone or in admixture of two or more.

The coating method used when the photosensitive composition of the present invention is provided on the surface of a support is a conventionally known method, for example, spin coating, wire bar coating, dip coating, air knife coating, roll coating, blade coating. It is also possible to use curtain coating and the like. The coating amount varies depending on the use, but is preferably 0.1 to 5.0 g / m ² (as solid content). The drying temperature is, for example, 20 to 150 ° C, preferably 30 to 100 ° C.

In the present invention, the coating amount of the photosensitive coating liquid on the support varies depending on the use, but generally a solid content of 0.5 to 3.5 g / m ² is suitable.

The support on which the photosensitive layer using the photosensitive composition of the present invention is provided is a metal plate of aluminum, zinc, steel, copper or the like, and chromium, zinc, copper, nickel, aluminum, iron or the like is plated or Examples thereof include vapor-deposited metal plates, papers, plastic films and glass plates, papers coated with a resin, papers coated with a metal foil such as aluminum, and plastic films subjected to hydrophilic treatment. Among these, an aluminum plate is preferable. It is more preferable to use an aluminum plate which has been subjected to surface treatment such as graining treatment, anodizing treatment and optionally sealing treatment as a support of a photosensitive lithographic printing plate using the photosensitive composition of the present invention. preferable.

Known methods can be applied to these treatments.

Examples of the graining method include a mechanical method and an electrolytic etching method. Examples of the mechanical method include a ball polishing method, a brush polishing method, a liquid honing polishing method, and a buff polishing method. The above-mentioned various methods can be used alone or in combination depending on the composition of the aluminum material. The method by electrolytic etching is preferable.

Electrolytic etching is performed using phosphoric acid, sulfuric acid, hydrochloric acid,
It is carried out in a bath containing an inorganic acid such as nitric acid or a mixture of two or more kinds. After the graining treatment, if necessary, desmut treatment is performed with an aqueous solution of alkali or acid to neutralize and wash with water.

The anodic oxidation treatment is carried out by using sulfuric acid, chromic acid, oxalic acid, phosphoric acid, malonic acid or the like as an electrolytic solution, either alone or in combination.
It is carried out by electrolysis using a solution containing at least one species and using an aluminum plate as an anode. The amount of anodized film formed is 1 to 50
mg / dm ² are suitable, preferably from 10 to 40 mg / dm ^2. The amount of anodic oxide film is, for example, a phosphoric acid chromic acid solution (phosphoric acid 85% solution: 35 ml, chromium oxide (V
I): 20 g is dissolved in 1 liter of water to prepare), the oxide film is dissolved, and the weight change of the plate before and after film dissolution is measured.

Specific examples of the sealing treatment include boiling water treatment, steam treatment, sodium silicate treatment, and dichromate aqueous solution treatment. In addition to this, the aluminum plate support may be subjected to undercoating treatment with a water-soluble polymer compound or an aqueous solution of a metal salt such as fluorinated zirconic acid.

The support provided with the photosensitive layer using the photosensitive composition of the present invention can be subjected to a hydrophilizing treatment with nitrite after the graining treatment and the anodizing treatment.

Examples of nitrites are Ia and I of the periodic table.
Examples include nitrites or ammonium salts of metals of groups Ia, IIb, IIIb, IVa, IVb, VIa, VIIa, and VIII, that is, ammonium nitrite. Examples of the metal salts include Li
NO ₂ , NaNO ₂ , KNO ₂ , Mg (NO ₂ ) ₂ , Ca (NO ₂ ) ₂ , Zn (NO ₂ ) ₂ , Al
(NO ₂ ) ₃ , Zr (NO ₂ ) ₄ , Sn (NO ₂ ) ₄ , Cr (NO ₂ ) ₃ , Co (NO ₂ ) ₂ , Mn
(NO ₂ ) ₂ , Ni (NO ₂ ) _{2 and the} like are preferable, and alkali metal nitrite is particularly preferable. Of course, two or more kinds of such nitrites can be used in combination, and further, they can be used in combination with nitrous acid. In the present invention, it is preferable that the nitrite is generally contained in an aqueous solution containing these in an amount of 0.001 to 1.0% by weight.

The treatment conditions for treating the surface of the support with the above treatment liquid are as follows: the pretreated support is immersed in the temperature range of room temperature to about 100 ° C. for 10 to 300 seconds, or the treatment is performed. It is preferable to apply the liquid to the support.

The aluminum plate treated with the above nitrite is then steamed, water at 50 to 100 ° C. or 50 to 100 ° C.
The base treatment can be performed with the diluted alkaline solution. The aluminum support which has been subjected to the hydrophilic treatment with nitrite retains the characteristics of its hydrophilic surface and also has an enhanced adhesive force by this base treatment.

When the treatment with steam is performed, the temperature is preferably 120 ° C. or lower. The pH of dilute alkaline solution is
The range of 7.5 to 13.0 is preferable, and any alkali agent may be used as long as it has this pH range. Representative alkali agent, M (OH) n, M (CO 3) n, M
_{(CH 3 COO) n, M} (BO 3) n, Mm hydroxide represented by the general formula (PO _3), carbonates, acetates and the like are used (where M is ammonium, alkali metal and alkaline earth Represents a metal, and n and m are integers of 1 to 3).
Also, alkaline organic acid salts such as sodium gluconate, sodium tartrate, potassium tartrate can be used, and NR ₃
It is also possible to use an amino compound represented by the general formula (1) (for example, monoethanolamine). Treatment with an alkaline solution having a pH higher than 13.0 will dissolve the anodized film.

In the case of treatment with water or a dilute alkaline solution, if the treatment liquid temperature is lower than 50 ° C., a sufficient effect cannot be obtained even after long-term treatment, and only a printing plate having low printing durability can be obtained. Therefore, the treatment temperature is set to 50 to 100 ° C, and when using a dilute alkaline aqueous solution, a slightly lower temperature, namely 50
~ 80 ° C is preferred.

On the other hand, the treatment time is
In any case of treatment with water at 50 to 100 ° C. or dilute aqueous alkaline solution at 50 to 100 ° C., 1 to 120 seconds is suitable, and 5 to 30 seconds is particularly preferable.

As described above, the aluminum support treated with nitrite and then treated with steam or water at 50 to 100 ° C. or a dilute alkaline solution is then preferably dried.

The support subjected to the above treatment may be provided with a primer layer and the like, if necessary.

For the primer layer, for example, polyester resin, vinyl chloride-vinyl acetate copolymer, acrylic resin,
Examples thereof include vinyl chloride resin, polyamide resin, polyvinyl butyral resin, epoxy resin, acrylate-based copolymer, vinyl acetate-based copolymer, phenoxy resin, polyurethane resin, polycarbonate resin, polyacrylonitrile butadiene and polyvinyl acetate.

As the anchor agent constituting the primer layer, for example, a silane coupling agent, a silicone primer or the like can be used, and organic titanate or the like is also effective.

The photosensitive lithographic printing plate using the photosensitive composition of the present invention can be developed by a usual method. For example, it is exposed through a transparent positive film with a light source such as an ultra-high pressure mercury lamp, a metal halide lamp, a xenon lamp or a tungsten lamp, and then developed with various alkaline developers. As a result, only the unexposed portion remains on the surface of the support, and a positive-positive relief image is formed.

Examples of the alkaline developer include alkali metal salts such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium metasilicate, potassium metasilicate, dibasic sodium phosphate, and tribasic sodium phosphate. An aqueous solution of The concentration of the alkali metal salt is preferably 0.1 to 20% by weight. Further, an organic solvent such as an anionic surfactant, an amphoteric surfactant or alcohol can be added to the developing solution, if necessary.

[0079]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded.

<Production of Aluminum Plate> An aluminum plate having a thickness of 0.24 mm (material 1050, tempered H16) was immersed in a 5% caustic soda aqueous solution, degreased at 65 ° C. for 1 minute, and then washed with water.

The degreased aluminum plate was immersed in a 10% hydrochloric acid aqueous solution at 25 ° C. for 1 minute for neutralization and then washed with water. Then, this aluminum plate was immersed in a 0.3 mol / liter nitric acid aqueous solution at 30 ° C. under an alternating current with a current density of 50 A / dm ² .
After electrolytic surface roughening for 30 seconds, desmutting treatment was performed at 60 ° C. for 10 seconds in a 5% caustic soda aqueous solution. afterwards,
The surface of the aluminum plate is anodized in a 20% sulfuric acid solution at a temperature of 20 ° C., a current density of 3 A / dm ² , and a treatment time of 1 minute, and then hot water at 80 ° C. is used for 20 seconds. A sealing treatment was applied.

The aluminum plate which has been subjected to the above pretreatment is
% Sodium nitrite aqueous solution at 80 ° C. for 30 seconds.
After washing with water, it was dried at 80 ° C. for 3 minutes.

A coating solution of a photosensitive composition having the following composition was applied to the support prepared as described above using a wire bar and dried at 80 ° C. for 2 minutes. The coating amount of the dry coating film is 22 mg / dm ² .

(Coating Liquid for Photosensitive Composition) (Example 1) Novolac resin * A 7.76 g Compound of the present invention * 1 3.3 g Surfactant * B 0.13 g Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.11 g Halogen free radical producing compound * C 0.13 g Acid * D 0.52 g Methyl cellosolve 100 g

(Example 2) Novolac resin * A 7.76 g Compound of the present invention * 2 3.3 g Surfactant * B 0.13 g Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.11 g Compound that produces a halogen free radical * C 0.13 g Acid * D 0.52 g Methyl cellosolve 100 g

Example 3 The following coating solution was applied to the support of Example 1 to prepare a photosensitive lithographic printing plate. Novolac resin * A 7.76 g Compound of the present invention * 5 3.3 g Surfactant * B 0.13 g Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.11 g Halogen free radical producing compound * C 0.13 g Acid * D 0.52 g Methyl cellosolve 100 g

Example 4 The following coating solution was applied onto the support which was not hydrophilized with nitrite in Example 1. Novolac resin * A 7.76 g Compound of the present invention * 5 3.3 g Surfactant * B 0.13 g Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.11 g Halogen free radical producing compound * C 0.13 g Acid * D 0.52 g Methyl cellosolve 100 g

Comparative Example 1 The following coating solution was applied to the support of Example 1 to prepare a photosensitive lithographic printing plate. Novolac resin * A 7.76 g o-quinonediazide compound * 3 3.3 g Surfactant * B 0.13 g Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.11 g Halogen free radical producing compound * C 0.13 g Acid * D 0.52 g Methyl cellosolve 100 g

Comparative Example 2 A photosensitive lithographic printing plate was prepared in the same manner as in Example 1 except that the support of Comparative Example 1 was coated with the following photosensitive composition. Novolac resin * A 7.76 g o-quinonediazide compound * 4 3.3 g Surfactant * B 0.13 g Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.11 g Compound producing halogen free radical * C 0.13 g Acid * D 0.52 g Methyl cellosolve 100 g

Comparative Example 3 A photosensitive lithographic printing plate was prepared by coating the following photosensitive composition on the support of Example 1 which was not treated with nitrous acid. Novolac resin * A 7.76 g o-quinonediazide compound * 6 3.3 g Surfactant * B 0.13 g Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.11 g Compound producing halogen free radical * C 0.13 g Acid * D 0.52 g Methyl cellosolve 100 g

Comparative Example 4 The support of Example 1 was coated with the following photosensitive composition to prepare a photosensitive lithographic printing plate. Novolac resin * A 7.76 g o-quinonediazide compound * 7 3.3 g Surfactant * B 0.13 g Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.11 g Halogen free radical producing compound * C 0.13 g Acid * D 0.52 g Methyl cellosolve 100 g

* A: Novolac resin [phenol, m-
Cresol and a copolymer resin of p-cresol and formaldehyde (molar ratio of phenol: m-cresol: p-cresol = 2.0: 4.8: 3.2, Mw = 6500, Mw / Mn
= 5.4)] * B Surfactant: polyethylene glycol * C Compound that produces a halogen free radical: 2- [1-methyl-2- (benzo [C] -furan-2-yl) vinyl] -5- (trichloro methyl) -1,3,4-oxadiazole * D acid: veratric acid _{((CH 3 O) 2 C} 6 H 3 COO
H)

[0093]

[Chemical 7]

[0094]

[Chemical 8]

[0095]

[Chemical 9]

The photosensitive lithographic printing plate thus obtained was subjected to a sensitivity measurement step tablet (No. 2, Eastman Kodak Company, gray scale of 21 steps with 0.5 density difference each).
And a 2KW metal halide lamp (Idlefin 2000, manufactured by Iwasaki Electric Co., Ltd.) was used as a light source and exposed from a distance of 90 cm.

This exposed photosensitive lithographic printing plate was used as a commercially available developer (SPR-1, diluted 6 times by Konica Corporation,
The development was carried out at a developing time of 20 seconds and a developing temperature of 27 ° C., and the contrast was evaluated.

The "number of clear steps" in the evaluation of the high contrast is
The step number of the step tablet which has been completely developed, and the "solid step number" means the number of step which is not completely developed of the step tablet. Hardness is evaluated by the value of the number of solid steps-the number of clear steps. The smaller this value, the better the hardness.

Next, in order to examine the developability, the developability with the under developer and the developability with the over developer were evaluated.

[0100]

[Table 1]

* ¹⁾ Hard tone number of solid steps-number of clear steps = 7.0 or less ○ Number of solid steps-number of clear steps = 7.0 to 10.0 △ Number of solid steps-number of clear steps = greater than 10.0 ×

* ²⁾ Developability Underdevelopability: Development is usually SDR-1 manufactured by Konica Corporation.
A developer diluted with water 6 times is developed at 27 ° C. for 20 seconds. When evaluating the underdeveloping property, a developer having a further diluted alkali concentration, that is, a developer having a reduced developing ability is used. The developability with respect to the developing solution corresponding to is evaluated. For example, the dilution rate is changed to 9, 10, 11 times. A sample completely developed up to 11-fold dilution is marked with O, a sample completely developed up to 10-fold dilution is marked with Δ, and a sample completely developed up to 9-fold dilution is marked with X.

Over-developing property: standard developing solution (SD
R-1, 6-fold dilution) Replenisher SDR-1R4 to 15 liters
Evaluation is carried out using a developing solution supplemented with a double dilution solution at a rate of +2 liters. At the time of evaluation, the judgment is made based on the change value of the number of solid steps of standard gray scale and the number of solid steps at the time of over development. Change value of the number of solid steps within 1.0 ○ Change value of the number of solid steps 1.0 to 2.0 △ Change value of the number of solid steps 2.0 or more ×

[0104]

As described above in detail, it can be seen that the photosensitive composition of the present invention can provide good contrast and developability.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Onuma 1 Sakura-cho, Hino-shi, Tokyo Konica Co., Ltd. (72) Inventor Mitsuru Sasaki 1000 Kamoshida-cho, Midori-ku, Yokohama, Kanagawa Sanryo Kasei Co., Ltd. In-house (72) Inventor Jiro Uemura Sanyo Kasei Co., Ltd.

Claims (2)

[Claims] 1. A photosensitive composition containing an orthoquinonediazide compound having a molecular weight of 3000 or more and a mixture of a compound obtained by condensing an orthoquinonediazide sulfonyl halide and trihydroxybenzophenone. 2. A condensation product of a pyrogallol-acetone resin having a molecular weight of 3000 or more and an orthoquinone diazide sulfonyl halide, and a pyrogallol of a molecular weight of 2000 or less.
A photosensitive composition containing a mixture of an acetone resin and a condensation product of orthoquinone diazide sulfonyl halide.